Five Major Misconceptions about Evolution
From www.talkorigins.org
The five propositions below seem to be the most common misconceptions based on a Creationist
version of evolution. If you hear anyone making any of them, chances are excellent that they
don't understand the theory of evolution enough to make informed opinions about it.
• Evolution has never been observed.
• Evolution violates the 2nd law of thermodynamics.
• There are no transitional fossils.
• The theory of evolution says that life originated, and evolution proceeds, by
random chance.
• Evolution is only a theory; it hasn't been proved.
"Evolution has never been observed."
Biologists define evolution as a change in the gene pool of a population over time. One example
is insects developing a resistance to pesticides over the period of a few years. Even most
Creationists recognize that evolution at this level is a fact. What they don't appreciate is that this
rate of evolution is all that is required to produce the diversity of all living things from a common
ancestor.
Speciation (the creation of new species has been observed many times in all kingdoms (animalia,
plantae, protista, fungi and monera). What hasn't been observed is one animal abruptly changing
into a radically different one, such as a frog changing into a cow. This is not a problem for
evolution because evolution doesn't propose occurrences even remotely like that. In fact, if we
ever observed a frog turn into a cow, it would be very strong evidence against evolution.
"Evolution violates the 2nd law of thermodynamics."
This shows more a misconception about thermodynamics than about evolution. The second law
of thermodynamics says, "No process is possible in which the sole result is the transfer of energy
from a cooler to a hotter body." [Atkins, 1984, The Second Law, pg. 25] Now you may be
scratching your head wondering what this has to do with evolution. The confusion arises when
the 2nd law is phrased in another equivalent way, "The entropy of a closed system cannot
decrease." Entropy is an indication of unusable energy and often (but not always!) corresponds
to intuitive notions of disorder or randomness. Creationists thus misinterpret the 2nd law to say
that things invariably progress from order to disorder.
However, they neglect the fact that life is not a closed system. The sun provides more than
enough energy to drive things. If a mature tomato plant can have more usable energy than the
seed it grew from, why should anyone expect that the next generation of tomatoes can't have
more usable energy still? Creationists sometimes try to get around this by claiming that the
information carried by living things lets them create order. However, not only is life irrelevant to
the 2nd law, but order from disorder is common in nonliving systems, too. Snowflakes, sand
dunes, tornadoes, stalactites, graded river beds, and lightning are just a few examples of order
coming from disorder in nature; none require an intelligent program to achieve that order. In any
nontrivial system with lots of energy flowing through it, you are almost certain to find order arising
somewhere in the system. If order from disorder is supposed to violate the 2nd law of
thermodynamics, why is it ubiquitous in nature?
"There are no transitional fossils."
A transitional fossil is one that looks like it's from an organism intermediate between two lineages,
meaning it has some characteristics of lineage A, some characteristics of lineage B, and probably
some characteristics part way between the two. Transitional fossils can occur between groups of
any taxonomic level, such as between species, between orders, etc. Ideally, the transitional fossil
should be found stratigraphically between the first occurrence of the ancestral lineage and the
first occurrence of the descendent lineage, but evolution also predicts the occurrence of some
fossils with transitional morphology that occur after both lineages. There's nothing in the theory
of evolution which says an intermediate form (or any organism, for that matter) can have only one
line of descendents, or that the intermediate form itself has to go extinct when a line of
descendents evolves.
To say there are no transitional fossils is simply false. Paleontology has progressed a bit since
Origin of Species was published, uncovering thousands of transitional fossils, by both the
temporally restrictive and the less restrictive definitions. The fossil record is still spotty and
always will be; erosion and the rarity of conditions favorable to fossilization make that inevitable.
Also, transitions may occur in a small population, in a small area, and/or in a relatively short
amount of time; when any of these conditions hold, the chances of finding the transitional fossils
goes down. Still, there are still many instances where excellent sequences of transitional fossils
exist. Some notable examples are the transitions from reptile to mammal, from land animal to
early whale, and from early ape to human.
"The theory of evolution says that life originated, and evolution proceeds, by random
chance."
There is probably no other statement which is a better indication that the arguer doesn't
understand evolution. Chance certainly plays a large part in evolution, but this argument
completely ignores the fundamental role of natural selection, and selection is the very opposite of
chance. Chance, in the form of mutations, provides genetic variation, which is the raw material
that natural selection has to work with. From there, natural selection sorts out certain variations.
Those variations which give greater reproductive success to their possessors (and chance
ensures that such beneficial mutations will be inevitable) are retained, and less successful
variations are weeded out. When the environment changes, or when organisms move to a
different environment, different variations are selected, leading eventually to different species.
Harmful mutations usually die out quickly, so they don't interfere with the process of beneficial
mutations accumulating.
Nor is abiogenesis (the origin of the first life) due purely to chance. Atoms and molecules arrange
themselves not purely randomly, but according to their chemical properties. In the case of carbon
atoms especially, this means complex molecules are sure to form spontaneously, and these
complex molecules can influence each other to create even more complex molecules. Once a
molecule forms that is approximately self-replicating, natural selection will guide the formation of
ever more efficient replicators. The first self-replicating object didn't need to be as complex as a
modern cell or even a strand of DNA. Some self-replicating molecules are not really all that
complex (as organic molecules go).
Some people still argue that it is wildly improbable for a given self-replicating molecule to form at
a given point (although they usually don't state the "givens," but leave them implicit in their
calculations). This is true, but there were oceans of molecules working on the problem, and no
one knows how many possible self-replicating molecules could have served as the first one. A
calculation of the odds of abiogenesis is worthless unless it recognizes the immense range of
starting materials that the first replicator might have formed from, the probably innumerable
different forms that the first replicator might have taken, and the fact that much of the construction
of the replicating molecule would have been non-random to start with. (One should also note that
the theory of evolution doesn't depend on how the first life began. The truth or falsity of any
theory of abiogenesis wouldn't affect evolution in the least.)
"Evolution is only a theory; it hasn't been proved."
First, we should clarify what "evolution" means. Like so many other words, it has more than one
meaning. Its strict biological definition is "a change in allele frequencies over time." By that
definition, evolution is an indisputable fact. Most people seem to associate the word "evolution"
mainly with common descent, the theory that all life arose from one common ancestor. Many
people believe that there is enough evidence to call this a fact, too. However, common descent is
still not the theory of evolution, but just a fraction of it (and a part of several quite different theories
as well). The theory of evolution not only says that life evolved, it also includes mechanisms, like
mutations, natural selection, and genetic drift, which go a long way towards explaining how life
evolved.
Calling the theory of evolution "only a theory" is, strictly speaking, true, but the idea it tries to
convey is completely wrong. The argument rests on a confusion between what "theory" means in
informal usage and in a scientific context. A theory, in the scientific sense, is "a coherent group
of general propositions used as principles of explanation for a class of phenomena" [Random
House American College Dictionary]. The term does not imply tentativeness or lack of certainty.
Generally speaking, scientific theories differ from scientific laws only in that laws can be
expressed more tersely. Being a theory implies self-consistency, agreement with observations,
and usefulness. (Creationism fails to be a theory mainly because of the last point; it makes few
or no specific claims about what we would expect to find, so it can't be used for anything. When it
does make falsifiable predictions, they prove to be false.)
Lack of proof isn't a weakness, either. On the contrary, claiming infallibility for one's conclusions
is a sign of hubris. Nothing in the real world has ever been rigorously proved, or ever will be.
Proof, in the mathematical sense, is possible only if you have the luxury of defining the universe
you're operating in. In the real world, we must deal with levels of certainty based on observed
evidence. The more and better evidence we have for something, the more certainty we assign to
it; when there is enough evidence, we label the something a fact, even though it still isn't 100%
certain.
What evolution has is what any good scientific claim has--evidence, and lots of it. Evolution is
supported by a wide range of observations throughout the fields of genetics, anatomy, ecology,
animal behavior, paleontology, and others. If you wish to challenge the theory of evolution, you
must address that evidence. You must show that the evidence is either wrong or irrelevant or
that it fits another theory better. Of course, to do this, you must know both the theory and the
evidence.